They are implying that they have "killed" you - you are in big trouble with them, and they are going to make you pay for whatever you just did to them.
Nothing
I wouldn't be caught dead in sleeping during the class.
The idiom is "dead certainty". It means it's in the bag = this is a dead certainty = this is cinch
You are "Dead Meat"
It is actually an idiom.
This is not an idiom. Idioms make little or no sense unless you know the definition. This sentence makes perfect sense, so it is not an idiom. The dead fish smelled so bad that even as high as Heaven, you could smell them.
To be 'as dead as a donut' is to be utterly dead, devoid of life (when applied to people, plants or animals) or finished with, unusable (when applied to inanimate objects).
The opening line of the book, "Old Marley was dead as a doornail." Dead as a doornail is an idiom.
Things tend to be quiet at night, as if they were "dead." So if something is "dead as night," it means it is very quiet, not moving around, not making noise.
An animal that eats dead or rotting meat such as a Vulture.
The idiom "they froze in their tracks" means that they stopped what they were doing. Example- The robbers froze in their tracks when they heard the alarm.
The idiom "at a dead run" refers to moving with maximum speed or urgency, often implying a frantic or desperate pace. It can describe someone who is hurrying to complete a task or reach a destination quickly. The phrase emphasizes the intensity and rapidity of the action.